More marginal results and complications occur as a result of knee ligament surgery than of other common surgical procedure. Long-term success rates of anterior cruciate ligament reconstruction range between 75 and 90%. The goal of knee surgery is to restore the normal kinematics of the knee. If the tension is too high, the range of motion of the joint is restricted, resulting in abnormal stresses on the articular cartilage and the menisci, and interfering with the revascularization of the graft. The National Institute of Arthritis and Musculoskeletal and Skin Diseases Strategic plan for FY 2000-2004 lists recommended areas of research which include "research to better understand the environmental variables and patient variables affecting implant performance" and "determination of the optimal treatments and rehabilitation strategies for common sports injuries." The hypothesis of this Phase I application is that Raman spectroscopy can be used to measure the tension jn a ligament graft. This hypothesis is based on the measurements of Wang et al. (2000) who have observed shifts of Raman lines with tension in single rat-tail tendon fibers and our preliminary measurements. An instrument for measuring the Raman spectrum of ligaments and tendons will be constructed and used to collect in vitro data. Measurements of MCL and ACL ligaments as functions of applied stress will be used to demonstrate the feasibility of the proposed technique. [unreadable] [unreadable] [unreadable] [unreadable]